Quick release presser feet



July 29, 1969 KlLLlNGER ETAL 3,457,889

QUICK RELEASE PRESSER FEET Filed Sept. 20, 1967 INVENTORE Karl H. KiHinger Edward J. TuHman Wnness I v 'I l Q14, 4 1 me 19w ATTORNEY United States Patent 01 3,457,889 Patented July 29, 1969 ice 3,457,889 QUICK RELEASE PRESSER FEET Karl H. Killinger, Dover, and Edward J. Tullman, Union, N.J., assignors to The Singer Company, New York, N.Y., a corporation of New Jersey Filed Sept. 20, 1967, Ser. No. 669,167 Int. Cl. Db 29/12 US. Cl. 112-240 7 Claims ABSTRACT OF THE DISCLOSURE A screwless clamp arrangement that permits an operator quickly to release or secure a presser-foot to the presserbar of a sewing machine. The arrangement utilizes a resilient member that releasably clamps the shank of the presser-foot to the presser-bar.

BACKGROUND OF THE INVENTION The prior art discloses various types of quick release resser-foot securing means including the screwless variety. The present invention is an improvement over such prior art devices. Certain of such prior art devices are relatively expensive to produce due to costly production methods required to manufacture the devices. Other prior art devices are relatively difficult to use and still others were sufficiently bulky to interfere with the operators view of the stitching point or work material. In some such prior art devices elements of the device are apt to loosen and become separated from the rest of the device causing the operator to waste time trying to locate the elements and then assemble the device.

SUMMARY OF THE INVENTION The present invention comprises a sewing machine presser-bar formed in its lower end section with a substantially vertical slot adapted to receive the shank of a presser-foot. The presser-foot is releasably secured to the presser-bar by a resilient member mounted on the presserbar.

The present invention solves the problems set forth above by providing a device that is simple and inexpensive to manufacture. Thus, the manufacturer need only provide a conventional needle-bar formed in its lower end section with two slots and a groove, a pressure-foot shank formed to fit one of the slots, a stud formed from or attached to the shank and a conventional radially collapsing split ring. The present invention is convenient to utilize because to secure the presser-foot in its operative position the operator need merely grasp the presser-foot with his hand and insert the pressure-foot shank into the presserbar slot against the bias exerted by the ring. Since only one motion is required to mount or remove the presserfoot it can be accomplished very quickly and easily. The device of the present invention includes no elements that may loosen and become separated from each other and the only element that protrudes beyond the confines of the existing presser-bar is the split ring, which because of its small size offers practically no visual obstruction to the operator.

It is an object of the present invention to provide an improved quick release presser-foot securing means.

It is another object of the present invention to provide an improved screwless type of presser-foot clamping arrangement.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational side view of a portion of a sewing machine equipped with the elements that comprise the presser-foot clamping arrangement of the present invention.

FIG. 2 is a front elevational view of a section of the presser-bar and the resser-foot clamping arrangement of the present invention.

FIG. 3 is an exploded perspective view of the elements shown in FIG. 2.

FIG. 4 is a sectional view of a section of the presserbar of the present invention.

FIG. 5 is a sectional view taken substantially along lines 55 of FIG. 4.

'FIG. -6 is an enlarged sectional view taken substantially along line 66 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more in detail to the drawings there is shown in FIG. 1 a cylindrically shaped presser-bar 10 journaled in the head 12 of a sewing machine. The presserbar 10 is bifurcated at its lower end section to form two legs 14 having outer surfaces 16 and end faces 18 which faces are beveled to form surfaces 20 that merge into the outer surfaces 16 and end faces 18 of the legs. A vertical slot 22 defined by the legs 14 is rectangular in cross section and extends transversely of notches 24 which are formed in, and open out of, the faces 18 of the legs. The notches 24 appear in cross section as vertex-truncated triangles with the bases formed by the open ends of the notches. A groove 26 that extends around the circumference of the needle-bar is formed in the outer surfaces 16 near the top of the legs 14. A radially collapsing split ring 28 is disposed in the groove 26 which holds the ring against vertical movement on the needle-bar.

A resser-foot 30 is formed with a sole plate 32 to which is pivotally connected a substantially upstanding leg 34 formed with a shank 36 on its upper section. The shank 36- is rectangular in cross section and is formed with two oppositely disposed flat faces 38 and 40. A cylindrically shaped stud 42 is formed on and extends outwardly from the face 38 near the lower end of the shank 36. Although the depth of the shank 36 is substantially equal to the diameter of the resser-bar 10, the slot 22 reduces the diameter at that point so that when the shank 36 is inserted in the slot it protrudes outwardly of the surface of the presser-bar and is gripped by the split ring 28, as seen more clearly in FIG. 6.

The presently disclosed presser-foot arrangement has been designed to provide the operator with a means for rapidly exchanging resser-feet. Thus, to mount the presser-foot 30 the operator need only grasp the presser foot with one hand and slip the shank 36 into the slot 22, so that the stud 42 is vertically aligned with the notch 24 in the leg 14 on the left side (as viewed in FIG. 2) of the presser-bar, and then push the shank up as far as it will go. The mating of the stud 42 with the notch 24 in cooperation with the ring 28 prevents the presser-foot from pivoting forward or aft in the plane of the slot 22, or in other words, in the line of sewing. As the shank 36 is slipped into the slot 22 it slides into the ring 28 forcing the ring to expand radially in the area where the shank contacts the ring, thereby distorting the ring into an elliptical shape, as seen more clearly in FIG. 6. Thus, the shank is frictionally held by the ring at the point of ring-shank contact while the ring itself is held against vertical movement by the groove 26, thereby locking the presser-foot to the presser-bar.

To release the resser-foot the operator need only grasp the presser-foot with one hand and pull it down to free the shank 38 from the frictional grip of the ring 28. It is here noted that only a relatively small force is required to pull the shank free, therefore, any operator may easily remove or clamp the resser-foot to the resser-bar.

Having thus set forth the nature of this invention, what we claim herein is:

1. A quick release presser-foot arrangement for a sewing machine having a frame, comprising a presser-bar supported in said frame, a presser-foot which may be releasably secured to the presser-bar and a resilient member mounted on said presser-bar, said presser-bar being formed with a substantially vertical slot opening into at least one side wall of the presser-bar, said presser-foot having a shank formed to be received by said substantially vertical slot, means for supporting said resilient member on the resser-bar and for bringing said resilient member into operative relationship with said shank releasably to secure said presser-foot on said presser-bar, said means including a groove formed on said presser-bar to receive said resilient member, said resilient member being a radially collapsing split ring and said shank including a surface that protrudes through the slot opening in the side of the wall of the presser-bar to bring said shank into contact with said radially collapsing split ring, said ring acting to clamp said shank against said presserbar thereby to hold said shank against vertical movement relatively to said presser-bar.

2. A quick release presser-foot arrangement for a sewing machine having a frame, comprising a presser-bar supported in said frame, a presser-foot which may be releasably secured to the presser-bar and a resilient member mounted on said presser-bar, said presser-bar being formed with a substantially vertical slot, said resser-foot having a shank formed to be received by said substantially vertical slot, means for supporting said resilient member on the resser-bar and for bringing said resilient member into operative relationship with said shank releasably to secure said presser-foot on said presser-bar, said resilient member being a radially collapsing split ring and said presser-bar being formed with a notch that opens out of the lower face of the presser-bar and extends transversely of said slot, and including a stud formed in said shank, said stud being received by said notch in cooperation with said split ring to prevent movement of the shank in the vertical plane of the said slot.

3. In a sewing machine having a presser-bar and a resser-foot carried thereby, means for releasably clamping the presser-foot to the presser-bar, said means comprising a shank forming part of the presserfoot, the lower section of the presser-bar being formed with a substantially vertical shank receiving slot, opening out of the lower end face of the presser-bar, that bifurcates the lower section of the resser-bar, the lower section of the presserbar having formed in its outer face a groove that extends around the circumference of the resser-bar, said shank being formed to be received by said vertical presser-bar slot, and resilient means mounted in said groove and in frictional engagement with said shank for holding said shank within the vertical shank receiving slot against vertical movement relatively to said presser-bar.

4. In a sewing machine as set forth in claim 3 wherein said shank holding means includes a radially collapsing split ring which frictionally engages said shank when said Y shank is received by said slot.

5. In a sewing machine as set forth in claim 4 wherein said presser-bar is formed with a notch that opens out of the lower end face of the presser-bar and extends transversely of the slot and said shank is formed with a stud that engages said notch when the shank is inserted into the slot and the split ring, such arrangement preventing pivotal movement of the shank within the slot in the vertical plane of the slot.

6. In a sewing machine as set forth in claim 4 wherein said slot is rectangular in cross section, said shank is rectangular in cross section, said notch is a vertex-truncated triangle in cross section and said stud is cylindrical in shape.

7. A quick release presser-foot arrangement for a sewing machine having a frame, comprising a presser-bar supported in said frame, a presser-foot which may be releasably secured to the presser-bar and a resilient member mounted on said presser-bar, said presser-bar being formed with a substantially vertical slot, said presser-foot having a shank formed to be received by said substantially vertical slot, means for supporting said resilient member on the presser-bar and for bringing said resilient member into frictional engagement with said shank releasably to secure said presser-foot on said presser-bar.

References Cited UNITED STATES PATENTS 3,270,695 9/1966 Ross 112-240 3,326,160 6/1967 Murino 112240 FOREIGN PATENTS 362,301 5/1962 Switzerland.

PATRICK D. LAWSON, Primary Examiner 

